Even as its twin goes dark, Opportunity soldiers on unabated: The plucky NASA Mars rover, on planet for seven years now, just passed an impressive 30-kilometer milestone.

Next on its plate is the massive 14-mile-wide Endeavour crater, just two miles away.

The picture, while impressive, is not perfect. Cosmic rays have bombarded the rover more than usual lately and there is a power-related issue with the right front wheel. Nevertheless, the 3-month mission, now in year seven, has been incredible at every step of the way.